Ekologiya cheloveka (Human Ecology)

This review systematizes current knowledge on adaptation and maladaptation of pulmonary function and ventilation during physical exertion in cross-country skiers as endurance athletes. Recently, studies have pointed to a possible limiting role of the respiratory system in athletes’ physical performance and competitive outcomes; however, these studies remain scarce and at times contradictory. The review addresses both well-known changes, such as exercise-induced airway bronchoconstriction, and less-studied phenomena, including seasonal variability of pulmonary function in cross-country skiers. Exercise-induced bronchoconstriction is shown to be a common feature among professional skiers training in dry, cold climates and to occur in two distinct forms: asthmatic and non-asthmatic. At the same time, there is a lack of studies elucidating the impact of bronchoconstriction on the endurance of athletes. Changes in breathing reserve during exercise in skiers may serve as a valuable indicator of respiratory system maladaptation and adaptation to athletic training. The presence of confirmed annual variability in pulmonary function parameters should be taken into account when conducting studies and interpreting spirometric results. This review presents the first attempt at a comprehensive conceptualization of respiratory mechanisms limiting physical performance in athletes. Key factors restricting oxygen uptake during exercise in cross-country skiers include fatigue of respiratory and locomotor muscles, hypoxemia, and expiratory flow limitation. These findings are essential for developing more effective strategies to prevent pulmonary dysfunction and to maintain high levels of athletic performance.

BACKGROUND: Starting with the works of Erisman, many studies have addressed the physical development of the pediatric population of the Russian Federation. At the same time, the development of scientific schools focusing on this issue in Russia remains understudied. This study aims to address this gap by analyzing the publication activity of Russian researchers.

AIM: This work aimed to analyze Russian scientific schools studying the physical development of the pediatric population based on bibliometric mapping using The Lens database.

METHODS: Bibliometric science mapping was performed using The Lens scientific database. The search query included terms describing physical development in Russian and English. The dataset comprised 17,994 publication records from 1860 to July 1, 2025. Bibliometric mapping was conducted using VOSviewer 1.6.20; authors were ranked using the artificial intelligence-based service GigaChat 2.0; author clustering was carried out using the k-means clustering method.

RESULTS: The Russian school studying physical development of the pediatric population includes two interconnected branches—a hygienic branch and a pediatric one—linked through publications by Prof. А.А. Baranov (Doctor of Sciences in Medicine, Academician of the Russian Academy of Sciences) and Prof. L.S. Namazova-Baranova (Doctor of Sciences in Medicine, Academician of the Russian Academy of Sciences). Cluster analysis divided Russian hygienist authors into three clusters: cluster 1 includes authors with moderate publication activity and low citation counts (mean number of publications, 7; mean citations, 10–20: E.N. Mingazova, T.E. Borovik, M.Yu. Gavryushin, O.V. Tulyakova); cluster 2 comprises well-known authors (mean number of publications, 12–15; mean citations, 50–100: D.B. Nikityuk, T.M. Maksimova, V.P. Novikova, N.A. Skoblina, A.N. Zavyalova, O.L. Lukoyanova, V.L. Gritsinskaya); and cluster 3 consists of internationally recognized authors (mean number of publications, 6–8; mean citations, >200: V.R. Kuchma).

CONCLUSION: The study characterized the development trends of scientific schools focused on the physical development of the pediatric population in Russia and identified key hygienist researchers within these schools. Study limitations include potential language barriers in publication indexing and the use of a single scientific database.

BACKGROUND: The effect of new biological threats, such as COVID-19, on public health is still understudied. The development of an adapted public health model is an urgent scientific task. By integrating the experience of the COVID-19 pandemic, such model would enable a systematic mitigation of similar risks in the future.

AIM: This study aimed to develop and validate a health model by identifying key biopsychosocial factors affecting physical and mental health in the post-COVID period.

METHODS: To collect empirical data (n = 337), we used an original proprietary questionnaire and Diener’s Satisfaction with Life Scale (SWLS). The SWLS included self-assessments of physical and mental health in the post-COVID period, physical activity and communicative behavior, perceptions of the pandemic’s effects on various life domains, demographic parameters, and chronic disease status.

RESULTS: The findings show that all three types of factors, including biological, social, and psychological, affect both subjective physical and mental health with psychological factors having the greatest effect. The study highlights the significant contribution of psychological variables to the assessment of an individual’s health in the post-COVID period. Specifically, emotional stability and communicative behavior were the most significant factors of both physical and mental health during this time.

CONCLUSION: The model developed and validated in this study expands the understanding of post-COVID health status by integrating biological, social, and psychological factors. The study may be used as a basis for updating clinical guidelines and developing new targeted rehabilitation strategies.

BACKGROUND: Bivalve mollusks are an important species for commercial harvesting. However, in addition to beneficial nutrients, they may contain hazardous compounds. Persistent organic pollutants are considered one of the most dangerous classes of organic compounds in terms of their impact on the environment and human health.

AIM: This work aimed to assess the food safety of bivalve mollusks of the family Mytilidae from the Sea of Japan based on the content of persistent organic pollutants.

METHODS: The biological material consisted of soft tissues of four species of bivalve mollusks collected in different areas of Peter the Great Bay in 2017–2022: Crenomytilus grayanus (Dunker, 1853), Modiolus kurilensis (F.R. Bernard, 1983), Mytilus trossulus (A. Gould, 1850), and Mytilus galloprovincialis (Lamarck, 1819). The mass concentrations of organochlorine compounds in the biological material were determined using a Shimadzu GC-2010 Plus gas chromatograph equipped with an ECD.

RESULTS: Organic toxicants were detected in all studied samples at levels in the range of 0.00012–141.319 ng/g wet weight. The highest concentrations were found in the samples collected from Amur Bay. The levels of persistent organic pollutants detected in mollusks were substantially lower than the maximum permissible limits established by the Russian regulations, with median values ranging from 0.0002% to 2% of the maximum permissible concentration. Thus, the content of persistent organic pollutants in bivalve mollusks of the family Mytilidae does not pose a threat to human health.

CONCLUSION: According to the obtained data, the content of persistent organic pollutants in the soft tissues of bivalve mollusks of the family Mytilidae does not exceed the current regulatory standards of the Russian Federation. These hydrobionts may be used for human consumption. Nevertheless, given the detection of prohibited compounds in the studied samples, systematic monitoring of the accumulation of persistent organic pollutants in the soft tissues of commercially harvested species from the coastal waters of the Sea of Japan should be continued.